Frequently used in gas turbine engines is a variety of rotary seals which includes rotating members cooperating across a narrow gap with another member which is generally stationary. For example, such seals are used between stationary structural members and a rotating shaft or drum for the purpose of maintaining different pressures in chambers adjacent the seal. As described in U.S. Pat. No. 3,339,933 - Foster, issued Sept. 5, 1967, and elsewhere in the art, common rotary labyrinth-type seals are coated with plasma arc sprayed materials such as high temperature oxides, for example alumina. However, plasma sprayed alumina has been seen to spall during gas turbine engine operation because of thermal cycling or gas erosion or their combinations.